Ultrasound imaging is widely used to assist with needle placement in medical procedures in which a drug is to be delivered to a target region within the body, such as the case with peripheral nerve blocks. In such a procedure, ultrasound imaging is used to identify the target region and to visualize the needle to assist the physician in guiding the tip of the needle to the target region.
There are various drawbacks associated with current ultrasound-assisted drug delivery procedures. One such drawback relates to the positioning and holding of the drug delivery needle. Physicians typically use a freehand placement technique for positioning the needle using ultrasound guidance. In such a technique, the non-dominant hand (e.g., the left hand) is used to hold the ultrasound probe against the patient's skin and the dominant hand (e.g., the right hand) is used to guide the needle tip to the target region with reference to image data collected by the probe. The needle must be carefully manipulated by the physician using a dynamic process in order to position the tip within the target region. Once the needle tip has been placed in the correct position, the physician must hold the needle steady. When a single injection is to be administered, a further physician or a physician's assistant must depress a plunger to deliver the drug to the target region. When the drug is to be continuously delivered, the further physician or physician's assistant must pass a catheter through the needle so that the tip of the catheter is also placed in the target region. Such procedures are undesirable because multiple persons are needed to perform it correctly.
Another drawback of current ultrasound-assisted drug delivery procedures is that the ultrasound probe typically must be used with a sheath to maintain the sterility of the operating environment, and such sheaths are often both costly and cumbersome. In addition, the index matching gel that is used to ensure that ultrasonic waves can pass from the sheathed probe and into the patient is messy and can foul the operating environment.
As can be appreciated from the above description, it would be desirable to have apparatus that enables the physician to avoid one or more of the above-described drawbacks associated with current ultrasound-assisted drug delivery procedures.